Oil fired boilers



Sept 13, 1966 1.. R. LUCHFORD ETAL 3,272,135

OIL FIRED BOILERS 2 Sheets-Sheet 1 Filed Sept. 14, 1964 5 R O T N E v NI LAURENCE R. LUCHF'ORD THOMAS A. BABE/GE K M Aeeeai p 1966 L. R.LUCHFORD ETAL 3,272,185

OIL FIRED BOILERS Filed Sept. 14, 1964 2 Sheets-Sheet 2 FIGZ INVENTORSLAURENCE R. LUCHFORD THOMAS A. BABBAG-E United States Patent Claimspriority, application Great Britain, Sept. 18, 1963,

36,754/63 8 Claims. Cl. 122-115 This invention relates to boilers fordomestic and industrial purposes and more particularly to such boilersin which a plurality of fire tubes extend through a water space from acombustion chamber to a flue.

In such boilers, the fire tubes have been vertical and the burner forexample an oil burner has protruded beyond the plan area of the boilerthereby causing a waste of floor area. The connection of the flue to theboiler has also protruded from the back or side of the boiler, againcausing a waste of floor space.

It is an object of the present invention to provide a boiler of the kindreferred to in which waste of floor space is avoided or greatly reduced.

From one aspect, a boiler of the kind referred to in accordance with theinvention has fire tubes which slope forwardly and upwardly from the topof the combustion chamber and overhang a space in which the burner mayhe accommodated.

From another aspect, the invention provides a boiler of the kindreferred to in which the front wall of the water space is inclinedforwardly to overhang the burner, the axes of the fire tubes beingparallel to this front wall, and the connection of the flue to theboiler is at the top of the boiler above the space between the top ofthe rearmost tubes and the back wall of the boiler.

From yet another aspect, a boiler of the kind referred to has inaccordance with the invention a heat exchange portion comprising firetubes and a surrounding water space which is inclined to the vertical sothat the burner and the flue connection can be accommodated at leastpartially within the horizontal plan area of the heat exchange portion.

Other parts of the invention are embodied in the preferred form whichwill now be described in some detail by way of example with reference tothe accompanying drawings in which:

FIG. 1 is a central vertical section.

FIG. 2 is a section on the line AA of FIG. 1.

In this form, the boiler has a Water jacketed lower portion B withrefractory material 1 (which may be of tapering upwardly section, largerat the top to co-operate with expansion of gases) and forming acombustion space C in which is burnt oil injected by an oil burner (notshown) through a refractory lined aperture 2. The oil burner is attachedto this lower portion at the front and protrudes outwardly beyond theplan area of the combustion chamber. The walls 3, 4 of this lowerportion of the boiler are vertical and extend to the top of thecombustion space C, the upper front Wall 5 of the boiler slopesforwardly and overhangs part of the space occupied by the burner.

Water inlets 17 are provided into the water jacket of the combustionchamber on both sides thereof, and water outlets 18 are provided at thetop of the boiler.

The top 6 of the combustion chamber slopes upwardly and rearwardly atright angles to the top front wall 5 of the boiler and forms the bottomof a water space closed at the top by an upwardly and rearwardly slopingtop plate 7. A number of fire tubes 8 extend through this water spaceopening at their lower ends into the combustion space C and at theirupper ends into a flue space F. These fire tubes are arranged in rowsand have their axes parallel to the sloping front wall 5 of the waterspace.

The flue space is defined by the top plate 7 and the top 9 of the boilerwhich lies parallel to the top plate so that it slopes upwardly andrearwardly. Behind the back row of fire tubes, both the top plate 7 andthe top 9 of the boiler are horizontal and a connection to the flue pipeis provided in this horizontal portion of the top of the boiler. Thisconnection comprises a cylindrical flange 10 surrounding an aperture inthe top of the boiler and lies wholly within the plan area of theboiler.

In the sloping portion 9 of the top of the boiler is provided anopening, closed by an insulated cover 12, through which direct access tothe flue tubes can be obtained for cleaning purposes.

The rear of the water space is defined by a 'back wall 13 which at thebottom slopes forwardly parallel to the front wall 5 and then slopesrearwardly to the top plate 7 of the water space. This depressionforwardly of the back wall directs the water into closer proximity tothe fire tubes 8, reduces the volume of the water in the Water space andincreases the strength of the plate to Withstand water pressure appliedto the boiler.

The fire tubes 8 are preferably of square section as shown but may ofcourse be rectangular, circular or oval as desired. Within each firsttube is mounted a retarder 14 which defines between it and the walls ofthe tube, passages of gradually decreasing section from the lower end ofthe retarder to the top of the fire tube.

The retarder may comprise a hollow metal member, closed at the bottomand with tapering walls, spaced from the walls of the fire tube byprojecting ribs. The closed bottom may be conical or pyramidal so as todeflect the combustion gases towards the surrounding tapered passages,thus not only to cause them to impinge on the inner face of the tubes,but also to eliminate the risk of turbulence at the lower end of theretarder, which could offer undesired resistance to the flow of gasesupwardly. Alternatively the retarder may comprise a refractory plug ofappropriate shape which may be hollow. The retarder may be provided witha lifting eye 15 at the top which may also serve to locate the retarderin the tube.

A pressure relief and draft-stabiliser flap 16 may be fitted into therear plate 13 immediately below the outlet to the flue and is of suchconstruction that it can be inserted or withdrawn from within, thusenabling the boiler to be installed in close proximity to a wall at therear for space-saving purposes, which is the most desirable location forsuch a device by giving inlet access direct to the flue.

A pressure relief 16', serving also as a sight glass may be providedinto the combustion chamber above the fuel inlet opening. A safety valvefor the water system may be provided in the front wall of the boiler andwill lie wholly within the plan area of the boiler.

It will be apparent that the invention provides a boiler of relativelysmall dimensions, with regards height and width, as compared to its highefliciency and rated output.

By reducing the overall back-to-front dimension of the boiler plus theburner, not only is space gained by getting the flue outlet within theconfines of the boiler body, but sloping forwardly the rectangularinternal heattransfer passages, causes impingement of the gases andwater on the forwardly sloping faces as well as improved flow of gas andwater through the section. Upon reaching the top plates the gases andWater are deflected upwardly and rearwardly towards the flue outlet 10and water outlets 18.

It will be understood that the invention is not restricted to thedetails of the preferred form described by way of example which may bemodified without departure from the scope of the following claims.

We claim:

1. A boiler comprising a -'bottom wall, upwardly disposed front, rearand side walls having their lower portions inwardly spaced platesdefining a water jacket surrounding a combustion space, said front walland cooperating plate having an aperture therethrough for mounting aburner to extend forwardly beyond the front wall, said front wall havingan upper portion above said combustion space which is inclined upwardlyand forwardly to project beyond the lower portion, said rear wall havingan upper portion which inclines forwardly and upwardly for part of itsheight and inclines rearwardly and upwardly for the remainder of itsheight, a water space above said combustion space defined at the bottomby a lower header plate, at the top by an upper header plate, and bysaid inclined upper portion of the front wall and the upper portions ofsaid rear and side walls, said water space communicating with theinterior of said water jacket surrounding the combustion space, a fluespace between said upper header plate and a top wall spaced thereabove,and a plurality of flue tubes inclined forwardly and upwardly acrosssaid water space to communicate said combustion space with said fluespace.

2. A boiler according to claim 1 wherein the aXes of said fire tubes areparallel to the inclined upper portion of said front Wall.

3. A boiler according to claim 1 wherein said top wall is provided atits rear with an aperture for connection of a flue and located betweenthe tops of the rearmost fire tubes and the rear wall.

4. A boiler according to claim 1 wherein said upper portion of the rearwall which inclines forwardly and upwardly for part of its heightclosely surrounds the inclined fire tubes to restrict and incline thewater space, and that part of the upper portion of the rear wall whichinclines rearwardly accommodates a flue connection to the rear of theflue space and within the horizontal plan area of the combustion space.

5. A boiler according to claim 1 in which the fire tubes have parallelsides and are fitted with centrally located gas retarders definingpassages with said sides of upwardly tapering cross-section.

6. A boiler according to claim 1 in which a pressure relief valveaccessible through a flue outlet is fitted in the rear wall of theboiler.

7. A boiler according to claim 3 wherein said plurality of fire tubes issmall in number and each of said fire tubes has a relatively large crosssection and each is fitted with a removable gas retarder, said top wallhaving an aperture disposed over the tops of said fire tubes and aremovable closure therefor, whereby said fire tubes are accessible forrapid cleaning by lifting the retarders through the uncovered aperturein the top wall.

8. A boiler according to claim 7 wherein each retarder is provided witha lifting member at its top.

References Cited by the Examiner UNITED STATES PATENTS 2,038,123 4/1936Olson et al. 122-225 2,096,586 10/1937 Johnson 122l15 X 2,431,460 11/1947 Burkhart 122-155 2,466,188 4/1949 Turner l22109 2,708,915 5/ 1955Mendelburg l22-109 KENNETH W. SPRAGUE, Primary Examiner.

1. A BOILER COMPRISING A BOTTOM WALL, UPWARDLY DISPOSED FRONT, REAR ANDSIDE WALLS HAVING THEIR LOWER PORTIONS INWARDLY SPACED PLATES DEFINING AWATER JACKET SURROUNDING A COMBUSTION SPACE, SAID FRONT WALL ANDCOOPERATING PLATE HAVING AN APERTURE THERETHROUGH FOR MOUNTING A BURNERTO EXTEND FORWARDLY BEYOND THE FRONT WALL, SAID FRONT WALL HAVING ANUPPER PORTION ABOVE SAID COMBUSTION SPACE WHICH IS INCLINED UPWARDLY ANDFORWARDLY TO PROJECT BEYOND THE LOWER PORTION, SAID REAR WALL HAVING ANUPPER PORTION WHICH INCLINES FORWARDLY AND UPWARDLY FOR PART OF ITSHEIGHT AND INCLINES REARWARDLY AND UPWARDLY FOR THE REMAINDER OF ITSHEIGHT, A WATER SPACE